Actuator for mast legs on a drilling rig

ABSTRACT

A mast for a drilling rig and a method for operation thereof, in which the mast includes a first leg, a second leg, and a mast leg actuator coupled to the first leg and the second leg. The mast leg actuator is configured to expand so as to pivot the first and second legs apart, and the mast leg actuator is configured to collapse so as to pivot the first and second legs together.

BACKGROUND

Drilling rigs generally include a rig floor and a mast that raises upwards from the rig floor. Various components that support pipe handling, drilling, and pipe running activities are either positioned on the rig floor or are suspended or otherwise attached to the mast. In addition, a substructure supports the rig floor above the ground, e.g., in rigs designed for land-based operation. Various devices may be positioned between the rig floor and the ground, e.g., wellhead equipment, blowout preventers, etc.

Land rigs may be designed to be transported in segments and quickly assembled at a wellsite. For example, the substructure, rig floor, and mast (among other components) may be transported separately. The substructure may be collapsed, and the mast may be disassembled and transported in two or more segments. Upon arriving at the new wellsite, the substructure may be positioned on either side of a well location, and the rig floor positioned on the substructure. Next, the segments of the mast may be attached together and to the rig floor in a horizontal configuration, for example, by connecting the bottom segment to the rig floor, and then attaching the remaining mast segments thereto in sequence. Once constructed, the mast may be pivoted from horizontal to vertical, and then secured in the vertical position, generally by securing feet on the lower end of legs of the bottom of the mast to the rig floor. The rig floor may then be raised by expanding the substructure. It will be appreciated that this description is greatly simplified, and that various other structures, connections, etc., may be employed in constructing a drilling rig.

Regarding the connection of the mast to the rig floor, often the legs of the mast are moved apart from the transport position to an expanded position that aligns with anchor points on the rig floor. Actuators may be used to move the legs apart, and also to move the legs back together when disassembling the rig. However, these actuators are expensive and can be prone to failure.

SUMMARY

This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

Embodiments of the disclosure may provide a mast for a drilling rig. The mast includes a first leg, a second leg, and a mast leg actuator coupled to the first leg and the second leg. The mast leg actuator is configured to expand so as to pivot the first and second legs apart, and the mast leg actuator is configured to collapse so as to pivot the first and second legs together.

Embodiments of the disclosure may also provide a method including pivoting a first leg of a mast apart from a second leg of the mast using a mast leg actuator coupled to the first and second legs, receiving a first foot of the first leg and a first foot of the second leg into first connections on a rig floor, raising the mast from a horizontal orientation to a vertical orientation by pivoting the mast about the first connections, and receiving a second foot of the first leg and a second foot of the second leg into second connections on the rig floor, so as to secure the mast in the vertical orientation.

Embodiments of the disclosure may further provide a mast leg actuator including a first arm configured to be connected to a first leg of a mast of a drilling rig, a second arm configured to be connected to a second leg of the mast, the second arm being pivotally connected to the first arm, and a driver coupled to the first and second arms. The driver is configured to increase an angle between the first and second arms, so as to pivot the first and second legs apart.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present teachings and together with the description, serve to explain the principles of the present teachings. In the figures:

FIG. 1 illustrates a perspective view of a portion of a mast being connected to a rig floor using a mast leg actuator in an expanded position, according to an embodiment.

FIG. 2 illustrates a perspective view of a portion of the mast with the mast leg actuator in a collapsed configuration, according to an embodiment.

FIG. 3 illustrates a flowchart of a method for assembling and disassembling a mast and a rig floor of a drilling rig, according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to specific embodiments illustrated in the accompanying drawings and figures. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.

It will also be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first object could be termed a second object or step, and, similarly, a second object could be termed a first object or step, without departing from the scope of the present disclosure.

The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the invention and the appended claims, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It will be further understood that the terms “includes,” “including,” “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Further, as used herein, the term “if” may be construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context.

FIG. 1 illustrates a perspective view of a mast 10 in a horizontal orientation and pivotally connected to a rig floor 12, according to an embodiment. In particular, the mast 10 includes a first leg 14 and a second leg 16, each of which has a pair of feet 18, 20, 22, 24. The rig floor 12 includes connections 26, 28, 30, 32 that are configured to connect to the feet 18-24, e.g., via fasteners, such as pins. In the horizontal orientation of the mast 10, as shown, two of the feet 20, 24 are connected to two of the connections 26, 28, while two of the feet 18, 22 are not connected to the rig floor 12. This allows for the mast 10 to be raised (pivoted) from the horizontal orientation up to a vertical orientation. In the vertical orientation, the feet 18, 22 may be connected (e.g., again via pins or other fasteners) to the connections 30, 32.

The legs 14, 16 may each include inner, generally vertical beams 34, 36, respectively, as well as outer, generally vertical beams 35, 37, respectively. The legs 14, 16 may define a truss or lattice structure that incorporates the beams 34-37. For example, as shown, the inner beam 34 may connect to the outer beam 35 at a pivot point 39A, and the inner beam 36 may connect to the outer beam 37 at a pivot point 39B. Further, the inner beams 34, 36 may face one another, while the outer beams 35, 37 may face away from one another. A cross-member 38 may extend between the pivot points 39A, 39B. As such, in some embodiments, the legs 14, 16 may be pivotally connected to the cross-member 38.

It will be appreciated that such a lattice structure is merely an example of an embodiment of the legs 14, 16. In other embodiments, the legs 14, 16 may be solid beams or any other sort of steel (or any other suitable material) construction.

Further, a mast-raising cylinder 40 that is configured to raise the mast 10 may extend upwards, adjacent to or through the rig floor 12 and connect to at least one of the legs 14, 16. In some embodiments, the cylinder 40 may be configured to raise the rig floor 12 with respect to the ground, in addition to raising the mast 10. In other embodiments, a winch, drawworks, crane, or the like may be used to raise the mast 10 and/or the rig floor 12.

The mast 10 may further include a mast leg actuator 100, which is shown in an expanded configuration. The mast leg actuator 100 is configured to move the feet 18, 22 and the feet 20, 24 toward and apart from one another, selectively, by pivoting the legs 14, 16 with respect to the cross-member 38. The mast leg actuator 100 may include a driver 102. In the illustrated embodiment, the driver 102 may be a hydraulic cylinder, which may be connected on one end to the cross-member 38. In other embodiments, a motor or another linear or rotational actuator may be used. In hydraulic cylinder embodiments of the driver 102, the driver 102 may additionally incorporate or be connected to a source of hydraulic pressure (e.g., a hydraulic pump).

The mast leg actuator 100 may further include an expandable assembly 104 that is connected to the driver 102 and to the beams 34, 36 of the legs 14, 16. In the illustrated embodiment, the expandable assembly 104 includes a first arm 106 having a distal end 107 that is pivotally connected to the first leg 14, and a second arm 108 having a distal end 109 that is pivotally connected to the second leg 16. The arms 106, 108 may be pivotally connected together by a hinge 110. The driver 102, e.g., hydraulic cylinder, may be connected to the hinge 110.

As such, operation (in this case, extension and retraction) of the driver 102 may control the angle between the first and second arms 106, 108, and thus the distance between the distal ends 107, 109 thereof. In turn, the distance between the distal ends 107, 109 may control the distance between the feet 18-24. When the angle is approximately 180 degrees, as shown, the expandable assembly 104 may be considered fully expanded, but in other embodiments, other angles may represent the greatest expansion available. In some embodiments, the pivoting arms 106, 108 are locked in the fully-expanded position, e.g., using a pin. In some embodiments, the pivoting arms 106, 108 may be substituted with telescoping arms, a worm drive, or another type of mechanical linkage that allows a single driver 102 to pivot the legs 14, 16.

In the expanded configuration, the mast leg actuator 100 may position the feet 18, 20 and the feet 22, 24 a distance apart that coincides with the distance between the connections 26 and 28 and the connections 30 and 32. With the mast leg actuator 100 in the expanded configuration, the mast 10 may be received horizontally onto the rig floor 12, such that the feet 18 and 20 are received into connection with the connections 26, 28, and pivotally secured thereto. The cylinder 40 (or another mast-raising device) may then raise the mast 10, such that the feet 22 and 24 are received into connection with the connections 30, 32 when the mast 10 reaches a vertical orientation.

FIG. 2 illustrates a perspective view of the mast leg actuator 100 in a collapsed configuration, according to an embodiment. As shown, the driver 102 is contracted (in the illustrated, hydraulic cylinder embodiment) in comparison to FIG. 1. As such, the driver 102 pulls the hinge 110 toward the cross-member 38. In turn, this decreases the angle between the pivotal arms 106, 108, drawing the distal ends 107, 109 thereof closer together, and, accordingly, draws the legs 14, 16 together. In an embodiment, the legs 14, 16 may be drawn together such that the inner beams 34, 36 touch, or until the outer beams 35, 37 are aligned with the lateral extents 200, 202 of the remainder of the mast 10.

As such, it will be seen that the mast leg actuator 100 includes a single driver (e.g., the driver 102), which is configured to pivot the legs 14, 16 together and apart, upon selection. In other embodiments, two or more such drivers of the mast leg actuator 100 may be used, for example, one driver to pivot the arms 106, 108 apart, and one to pivot the arms together, or separate drivers to control the position of the individual arms 106, 108. Further, the mast 10 may include various other actuators for various other reasons, but may be free from actuators, apart from the mast leg actuator 100, configured to pivot the first and second legs 14, 16 together or apart.

FIG. 3 illustrates a flowchart of a method 300 for assembling a drilling rig, according to an embodiment. In some embodiments, the method 300 may be executed using an embodiment of the mast 10, rig floor 12, and/or mast leg actuator 100 discussed above, and will thus be described herein with reference thereto. However, it will be appreciated that some embodiments of the method 300 may be executed using other structures.

The method 300 may begin by pivoting the legs 14, 16 of the mast 10 apart using the mast leg actuator 100, as at 302. For example, the mast 10 may initially be in a horizontal orientation, as shown in FIG. 1. The mast 10 may be disconnected and separated from the rig floor 12 at this point. Further, the mast leg actuator 100 may initially be in the collapsed configuration. To pivot the legs 14, 16 apart at 302, the driver 102 may actuate and expand the expandable assembly 104, thereby driving the legs 14, 16 apart (e.g., pivoting the legs 14, 16 such that the feet 18, 20 are driven away from the feet 22, 24) to the position illustrated in FIG. 2.

With the mast leg actuator 100 in the expanded configuration, and the legs 14, 16 pivoted apart, the method 300 may then proceed to receiving two feet 20, 24 into connection with connections 26, 28 on the rig floor 12, as at 304. This may proceed by moving the mast 10 (or a lower section thereof) horizontally, e.g., along the ground, such as by backing up a truck. Pins or other fasteners may be employed to secure the feet 20, 24 into connection with the connections 26, 28, while the mast 10 remains pivotal with respect to the rig floor 12.

The mast 10 may then be raised (pivoted upwards) from the horizontal orientation to the vertical orientation, as at 306. This may occur by expanding a mast-raising cylinder 40, or using a winch, drawworks, crane, etc. A variety of mast-raising devices may be suitable for different rigs.

Raising the mast 10 may result in the feet 18, 22 being received into the connections 30, 32 of the rig floor 12, and they may be connected thereto, as at 308. For example, the feet 18, 22 may be secured into the connections 30, 32 using fasteners such as pins or the like.

At this point, the mast 10 is secured to the rig floor 12 in the vertical orientation. Various other devices may be employed to further secure the mast 10 thereto. Further, a remaining rig construction sequence (“rig-up”) may then occur, e.g., connecting various structures, such as control cabins, pipe handling equipment, pipe gripping and running equipment, etc. The rig floor 12 may also be elevated from the ground by expanding a substructure, and equipment may be received into the basement between the ground and the rig floor. Drilling, completion, treatment, and other operations may then occur, using the rig floor 12 and the mast 10, among other equipment. When such operations are complete, the drilling rig, including the mast 10 and the rig floor 12, may be disassembled.

Accordingly, two of the feet, e.g., the feet 18, 22 may be disconnected from their connections 30, 32 with the rig floor 12, as at 310. Next, the mast 10 may be lowered back to the horizontal orientation, as at 312, e.g., again using the mast-raising cylinder 40. The other two feet 20, 24 may then be disconnected from their connections 26, 28, as at 314. The mast 10 may then be moved away from the connections 26, 28, and the legs 14, 16 may be pivoted together by collapsing the mast leg actuator 100, as at 316.

The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. Moreover, the order in which the elements of the methods described herein are illustrate and described may be re-arranged, and/or two or more elements may occur simultaneously. The embodiments were chosen and described in order to explain at least some of the principals of the disclosure and their practical applications, to thereby enable others skilled in the art to utilize the disclosed methods and systems and various embodiments with various modifications as are suited to the particular use contemplated. 

1. A mast for a drilling rig, comprising: a first leg; a second leg; and a mast leg actuator coupled to the first leg and the second leg, wherein the mast leg actuator is configured to expand so as to pivot the first and second legs apart, and wherein the mast leg actuator is configured to collapse so as to pivot the first and second legs together.
 2. The mast of claim 1, wherein the mast leg actuator comprises: an expandable assembly having first and second distal ends, the first distal end being connected to the first leg and the second distal end being connected to the second leg; and a driver coupled to the expandable assembly and configured to move the first and second distal ends together and apart.
 3. The mast of claim 2, wherein the expandable assembly comprises a first arm and a second arm, the first and second arms being pivotally connected together.
 4. The mast of claim 3, wherein the first arm comprises the first distal end, and the second arm comprises the second distal end.
 5. The mast of claim 4, wherein first distal end is pivotally connected to the first leg, and wherein the second distal end is pivotally connected to the second leg.
 6. The mast of claim 2, further comprising a cross-member extending between the first and second legs, the first and second legs being pivotal relative to the cross-member, wherein the driver is connected to the cross-member.
 7. The mast of claim 6, wherein the driver comprises an extendable cylinder connected to the cross-member, and wherein the expandable assembly comprises a first arm, a second arm, and a hinge that pivotally connects the first and second arms together, the extendable cylinder being connected to the hinge.
 8. The mast of claim 1, further comprising feet that are connectable to connections on a rig floor, wherein, when the mast leg actuator is in an expanded configuration, the feet are aligned with the connections, and wherein, when the mast leg actuator is in a collapsed configuration, the feet are closer together than the connections.
 9. The mast of claim 1, wherein the mast leg actuator comprises a single actuator configured to pivot the first and second legs apart, and to pivot the first and second legs together, and wherein the mast does not include any other actuators configured to pivot the first and second legs relative to one another.
 10. A method, comprising: pivoting a first leg of a mast apart from a second leg of the mast using a mast leg actuator coupled to the first and second legs; receiving a first foot of the first leg and a first foot of the second leg into first connections on a rig floor; raising the mast from a horizontal orientation to a vertical orientation by pivoting the mast about the first connections; and receiving a second foot of the first leg and a second foot of the second leg into second connections on the rig floor, so as to secure the mast in the vertical orientation.
 11. The method of claim 10, further comprising: disconnecting the second foot of the first leg and the second foot of the second leg from the second connections; and lowering the mast from the vertical orientation to the horizontal orientation by pivoting the mast about first foot of the first leg and the first foot of the second leg.
 12. The method of claim 11, further comprising: disconnecting the first foot of the first leg and the first foot of the second leg from the first connections; and pivoting the first and second legs together by collapsing the mast leg actuator.
 13. The method of claim 10, wherein pivoting the first leg apart from the second leg comprises increasing an angle between a first arm connected to the first leg and a second arm connected to the second leg using a driver connected to a hinge between the first and second arms.
 14. The method of claim 13, wherein the driver comprises a hydraulic cylinder, and wherein increasing the angle comprises extending the hydraulic cylinder.
 15. The method of claim 14, wherein the hydraulic cylinder is coupled to a cross-member connected to the first and second legs.
 16. A mast leg actuator, comprising: a first arm configured to be connected to a first leg of a mast of a drilling rig; a second arm configured to be connected to a second leg of the mast, the second arm being pivotally connected to the first arm; and a driver coupled to the first and second arms, wherein the driver is configured to increase an angle between the first and second arms, so as to pivot the first and second legs apart.
 17. The mast leg actuator of claim 16, further comprising a hinge that pivotally connected the first arm to the second arm.
 18. The mast leg actuator of claim 17, wherein the driver comprises an extensible hydraulic cylinder coupled to the hinge and to a cross-member extending between and pivotally coupled to the first and second legs.
 19. The mast leg actuator of claim 17, wherein the driver is configured to decrease an angle between the first and second arms, so as to pivot the first and second legs together.
 20. The mast leg actuator of claim 17, wherein the first arm comprises a distal end that is pivotally connected to the first leg, and wherein the second arm comprises a distal end that is pivotally connected to the second leg. 